Method of and apparatus for manufacturing artificial filaments



Jul 13,1926. 1592mm G. J. ROY

METHOD OF AND APPARATUS FOR-MANUFACTURING ARTIFICIAL FILAMENTS Filed Jan. 9, 1926 l I l l I l I l I 'I I I I ATTORNEY Patented July 13, 1926.

UNITED STATES 1,592,006 PATENT OFFICE.

GUSTAVE JEAN ROY, or LYON, FRANCE, AssIeNoR T sooin'rn noun LA FABRICATION 'DE LA'SOIE RHODIASETA, or PARIS, FRANCE, A CORPORATION or FRANCE.

METHOD OFoAND APPARATUS FOR MANUFACTURING ARTIFICIAL FILAMENTS.

Application filed January 9, 1926, Serial No. 80,383, and in Great Britain September 18, 1925.

In the manufacture of artificial threads by dry spinning of collodions the basis of which is esters, ethers or any cellulosic derivative, it is usual to obtain the evaporation of the solvents inside a closed or almost closed region of the spinning dies, independently.

of that of the remaining portion of the cell, has been stated, and, as means for attaining this result, Prince has pointed out the exhaust of the evaporating atmosphere at an intermediate region of the cell, and the introduction, in the neighborhood of the spinning dies, of a certain proportion of evaporating atmosphere the temperature of which is regulated.

The possibility of controlling the shape 2 of the section of the filaments, and avoiding the scintillating effect by a judicious selection of the temperature in the region of the spinning: dies, according to the conditions selected for performing the spinning, has also been disclosed in an application of Girardet, Serial No. 33,497, filed May 28, 1925. Finally, it has also been shown, in the application of Lahousse, Serial No. 739,972, filed September 26, 1924, in order .to obtain filaments with a round section, to expose the filaments, for evaporating the solvents, to the action of an atmosphere heavily laden with the volatile solvents entering into the t composition of the spun collodion. Y For this purpose, the evaporating atmosphere, instead of being admitted into the cell pure, or as free as possible from solvent vapors, is admitted thereto already heavily laden with 6 such vapors. The Lahousse application also describes how any loss of gas richly laden with solvent jvapors, through the orifice by which the spun filaments issue from the cell, may be avoided by creating in the cell a slight negative pressure, so as to cause thereby an extremely small inflow of fresh air,

reduced to the possible minimum.

The present invention relates to a new method by means of which it is possible to obtain in an extremely simple manner, si-

multaneously, the independent regulation of the temperature at the spinning dies and the spinning in an atmosphere richly laden with solvent vapors, along any desired length of travel of the filaments, and this,vcontrary to the procedure described in the application of Lahousse above referred to, while a relatively considerable amount of fresh. atmosphere is introduced into the cell for the purpose of the evaporation of' the solvents, which, atmosphere will work under specially favorable conditions.

The improved method consists in efiecting the tapping or withdrawing of atmosphere from the cell, at an intermediate region thereof, .andre-admitting this atmosphere into the cell in the vicinity of the region of the spinning dies, after having re-heated it to a suitable temperature if necessary.

For greater simplicity, I will hereinafter refer to the auxiliary movement so created as the derived circuit, in contradistinction -to the movement, which I shall call principal circuit, f the fresh atmosphere intro' duced by the outlet orifice of the filaments, or in the vicinity of this orifice. In reality,

there is naturally a mixing of the two c1rcuits in the regions of common travel,'but these designations remain nevertheless quite comprehensible. The output of the derived circuit will be that provided at the point of tapping or withdrawing of the atmosphere from the cell and consequently at the point of re-admittance into the cell at the region of the spinning dies. The rate of flow of the principal circuit will be that of the fresh atmosphere introduced into the cell, and, consequently, of the atmosphere finally exhausted for the recovery of solvents, withonly the difierence arising from the volume of solvents with which this atmosphere is laden.

As a first consequence of the adoption of this method, it will be seen that the derived circuit will participate in the evaporation of the solvents in the region of travel of the filaments where this evaporation is particularly intense. As the atmosphere ofthis derived circuit can be readmitted hot in the region of the spinning dies, its evaporating action will, in this case, thereby considerably increase. lar conditions of manufacture the 'quantity of fresh atmosphere introduced into the cell,

One result of this is that, for siminecessary in the absence of this derived circuit, is considerably reduced. Another result is that it is possible to evaporate considerably larger quantities of solvents for a similar rate of flow of fresh atmosphere introduced into the cell, and consequently, to s in with a much greater speed.

T is invention, therefore, provides a means of reducing the quantity of atmosphere used for the recovery of the vapor for a definite production, thereby increasing the concentration of the solvents to be recovered, which will constitute an important economy. AS a matter of fact, it is known that, in most rocesses for the recovery of vapors, the di ution of the atmosphere influences not only the final efliciency of the operation, but also the co-eflicient of utilization of the products used for the recovery.

Moreover, it will be immediately apparent that, owing to the present invention, a means is now obtained for causing the filament to perform the first portion of 1ts travel in-an-atmosphere particularly rich in solvent vapors, since the atmosphere tapped from the cell and re-admitted 1n the neighborhood of the spinning dies contains a certain percentage of solvents which adds itself to the amount resulting from the evaporation in that regionof travel of the filaments. For a definite position of the point of tapping of the derived circuit the proportion of vapors in the atmosphere at the spinnin dies will be varied by causing the rate of 50w of the. principal circuit and that of the derived circuit to vary with respect to each other. It will be particularly obvious from the spirit of the present invention that the derived circuit is given a large rate of flow, substantially greater than that of the principal circuit.

Similarly, if the rates of flow of the principal circuit and that .of the derived circuit are kept constant, the proportion of solvent vapors in the tapped atmosphere, and thereby the proportion of solvent vapors in the region of thespinning dies can be varied by varying the height of the point of tapping of the derived circuit and with respect to the height of the point of final exhaust of the evaporating circuit.

Finally, the present invention provides a very'simple means of adjusting to the required degree the temperature inthe region of the spinning dies by the regulation of the temperature of the atmosphere so re-ad mitted in this region, the rate of flow of which atmosphere, moreover, besides, may be varied between wide limits.

It will suffice, forgiven conditions of spinning, and for a'given rate of flow of the atmosphere in the derived circuit, to determine the temperature to which this atmosphere mustb'e' grfjiti'sed in order that its introvlett, No. 1,571,474,

duction in the region of the spinning dies may bring the temperature in that region to the desired degree. Of course, the heating so obtained in the region of the spinning dies by the introduction of this atmosphere may be combined with any other known arrangement also adapted to influence the temperature in the region of the spinning dies, such for instance as that described in the application of Girardet, Serial No. 33,497, hereinbefore referred to.

The details of'means'for carrying out the present invention can be of a widely varied nature. For instance, the individual tappings of each cell may be gathered together in a single collector for one or several groupsof cells, creating the flow by a propelling device of any type, and, by means of another collector, re-admit this atmosphere in the individual cells, the equality of the flow in the individual cells being preferably insured by the methods of simultaneous regulation, described in the patent to Grildated February 2, 1926. The heating of the atmosphere of the derived circuit may be insured at any suitable portion of the circuit, and the piping for the hot atmosphere may be suitably insulated to avoid losses of heat.

It will be obvious that an individual derived circuit may be provided for each spinningcell, the movement in this circuit being caused either by an individual propelling device or by the sole action of the densities. In the latter case, the flow may be regulated, within limits depending on the temperatures maintained at ditfrent positions of the circuit, by the arrangement and the dimensions of the piping system and the provision of identical dampers, constrictions, and like devices, identical for all cells where the same product is being manufactured.

Inorder to insure a symmetrical distribution of the gaseous current, it will be wise to effect the tapping and the re-admittan'ce of the atmosphere by annular passages, as described in the application of Prince, Serial No. 720,106, hereinbefore referred to.

The method according to the present inspecially sought by the presthe position of the filaments withmespect axially.

to the gaseous currents is obtained. The diameter of the cells is preferably reduced to a minimum, always having in mind a better utilization of the atmosphere, and the cell is provided at its lower end with a funnelshaped chamber, as described in the patent The cells may be constructed slightly tapered or converging towards the thread outlet, and such taper may extend along the wholeor only a part of the length of the cell, so as to correspond to the conical formation of the filaments as they extend from the spinning dies down to the outlet.

In the appended drawings, which illus-* trate'diagrammat1cally,'as an example only, the application of the method of the present invention to a group of cellsof the cylindrical type.

Fig. 1 is a diagrammatic side elevation of an apparatus having a'single cell;

Fig. 2 is a view similar to Fig. 1, butshowing an apparatus having a plurality of cells; and

Fig. 3'is a diagrammatic side view of a modified form of apparatus.

Referring-to the drawings, A designates the individual cells, the major portion ofeach of which is formed of a tube of thin .metal and of small diameter, which is particularly economical. The cell is preferably provided at its upper end with a portion of arger diameter which will serve not only to afford easyaccessto the spinning dies 3 by means of adoor (not shown) but also as a means for spacing the cells at a suitable distance apart so as to provide for sufficient space to accommodate the apparatus for winding, bobbining, etc., for the thread issuing from each cell.

' At their lower portion,

.heated by any known suitable means. In

the drawings, the cells areshown inclosed for a portion of their length by a jacket G forming a chamber around the cells, through which-chamber pass a plurality of tubes a through which any su1tab1e heating fluid may be circulated by means of which perfect regularity of heating from one end to the other of a group of cells 'may be insured. The cells A may, if desired, be provided with large perforations in the portions enclosed order to enhance the exwould be necessary to partition oflithe chamber between successive cells, in order to insure each cell an independent working.

The cells A maybe continued some distance below the heating chamber, in order is conducted through branch pipes the cells A are provided'with a hinged opening device as, descrlbed in the application of Prince, Serial .No. 720,106.

The atmosphere is tapped from the cell by means of an annular tubular member F encircling theccll at the propenpoint in its by the current of fresh: atmosphere I length and which is in communication-with the interior of the cell through a series of perforations as indicated in Fig. 1. atmosphere thus drawn from successivecells E into a collector'E, and from thence the derived atmosphere, after passing through a suitable'heating apparatus, is deliveredto a dis- The tributor G from whence it passes through branch pipes Gr bers H similar to the members F into the successive cells at a point near the region of the spinning dies. For the sake of simplicity the heating apparatus J by means of which the tapped atmosphere may be raised to any desired temperature, as well as the fan I for causing the circulation of the air are illustrated herein only diagrammatically. The heater may be placed at any suitable point of the circuit either on the distributor G-or on the individual branch pipes between the distributor and the member H of each cell. The atmosphere is exhausted from the cell'through a thirdv annular perforated member K, and is thence conducted a collector L, for the purpose of recovery. The'equality of the flow of all the several principal circuits and the equality of the flow of all the derived circuits in each cell in which a similar product is being manufactured may be insured, for instance, by the use of special means such as described in the application of Grillet, Serial No..

As a second example of the application of the present invention, Fig. 3 illustrates the upper portion of a cellular apparatus in vwhi h he derived circulation takes place independently for each cell, by the sole action of the differences of density caused by the heating of the derived circuit. In the cell shown in this figure, the tapping takes place at M and the re-admission' at N. In this modification. P designates a heating jacket enclosing the pipe through which the derived atmosphere passes from M to N the heating fluid being supplied to the jacket for all of, the cells by a distributorQ and being collected as it issues from the jacket by a collector R,- both Q, and R being careand annular tubular memfully thermally insulated. 'The exhaust of the atmosphere to the recovery apparatus takes place at S, and thence to vthe collector T.

Having thus described my invention, what I claim is 1. A process of manufacturing artificialfilaments from collodions the basis of which is a cellulose derivative, which consists in spinning the collodion through dies disposed within a practically closed cell, supplying said cell with'a gaseous medium intended to cause the evaporation of'the solventjan'd to be evacuated for recuperating said solvent therefrom, andcreating an auxiliary circulation of evaporating medium by tapping atmosphere from the cell at a point intermediate its ends,,a nd reintroducing said atmosphere into the cell at a point in the re gion of the dies.

2. A. process of manufacturing artificial filaments from collodions the basis of which is a cellulose derivative, which consists in' spinning the collodion through dies disposed within a practically closed cell, supplying said cell with a gaseous medium intended to cause evaporation of the solvent and to be evacuated for recuperating said solvent therefrom, and creating anauxiliary circu- 1 lation of evaporating medium by tapping atmosphere from the cell at a point intermediate its ends, passing said atmosphere through a heating apparatus, and reintroducing the heated atmosphere into the cell at a point in the region of the dies.

3. A process of manufacturing artificial filaments from collodions the basis of which i is a cellulose derivative, which consists in spinning the collodion through dies disposed within a plurality of practically closed cells, supplying each of said cells with a gaseous medium intended to cause the evaporation of the solvent and to be'evacuated for recuperating the solvent therefrom, and creating an auxiliary circulation of evaporating medium by tapping atmosphere from each of i said cells at a point intermediate its ends, collecting the atmosphere drawn off from each of the cells in a single collector, heating the collected atmosphere and reintroducing the heated atmosphere into the individual cells at a dies. 4. Apparatus for manufacturing artificial filaments from collodions, comprising a practically closed cell, dies disposedwithin said cell, means for supplying said cell with gaseous medium intended to cause the evaporation of solvents and to be evacuated for recuperating said solvents therefrom, and means for creating an auxiliary circulation of evaporating medium by withdrawing atmosphere from said cell at a point inter mediate its ends and reintroducing said atmosphere into the cell at a point in the region of the dies.

5. Apparatus for manufacturing artificial point in the region of the filamentsfrom collodions, comprising a practically closed cell, dies disposed within said cell, means for supplyingsaid cell with gaseous medium intended to cause the evaporation of solvents and to be evacuated for recuperating said solvents therefrom, means for creating an auxiliary circulation of evaporating medium by withdrawing atmosphere from said cell at a point intermediate its ends and reintroducing said atmosphere into the cell at. a point in the region of the dies, and means for heating said atmosphere for creating an auxiliary circulation of evap- I orating medium by withdrawing atmosphere from said cell at a point intermediate its ends and reintroducing said atmosphere into the cell at a point in the region of the dies, means for heating said atmosphere between its withdrawal from and its reintroduction into the cell, and means for heating the gaseous evaporating medium during its passage through the cell.

7 Apparatus for manufacturing artificial filaments from collodions, comprising "a practically closed cell, dies disposed at the upper part of said cell, means for supplying said cell with gaseous medium intended to cause the evaporation of the solvents and to be evacuated for recuperating said solvents therefrom, a piping connecting externally a point of the cell intermediate its ends with a point of said cell in the region of the dies and means for heating said piping between its connection with said cells.

8. Apparatus for manufacturing artificial filaments from collodions comprising a plurality of practically closed cells, dies disposed within each of said cells, means for supplying each of said cells with gaseous medium intended to cause the evaporation of the solvents and to be evacuated for recuperating said solvents therefrom, means for creating an auxiliary circulationof evaporating medium by withdrawing atmosphere from each of said cells at apoint intermediate its ends, a collector for receiving the atmosphere drawn off from all of said cells, a distributor in communication with said collector, andwith each ofsaid cells at a point in the region of its dies, and means for heating the atmosphere before its reintroduction into the cells.

In testimony whereof I have signed my name to this specification.

GUSTAVE JEAN ROY. 

